Photographic apparatus



1966 N. GOLD ETAL 3,266,404

PHOTOGRAPHIC APPARATUS Filed July 1963 4 Sheets-Sheet 1 INVE/Aggfi BY ATTORNEYS Aug. 16, 1966 N. GOLD ETAL Filed July 26, 1963 4 Sheets-Sheet 2 i INVE TORS.

ATTORNEYS Aug. 16, 1966 N GOLD ETAL I 3,266,404

PHOTOGRAPHIC APPARATUS Filed July 26. 1963 4 Sheets-Sheet 3 a, Q a 1 3% r z [w 0 I v N qr M @QW 0 @6 a I z v I' I LI FNVENTORS BY ;:;;i 44uz.

ATTORNEYS N. GOLD ETAL I PHOTOGRAPHIC APPARATUS Aug. 16, 1966 4 Sheet$-$heet 4 Filed July 26, 1963 FIGS.

d v l ATTORNEYS United States Patent 3,266,404 PHOTOGRAPHIC APPARATU Nicholas Gold, Arlington, and Arthur J. Sable, Boston, Mass., assignors to Polaroid Corporation, Cambridge, Mass., a corporation of Delaware Filed July 26, 1963, Ser. No. 297,768 18 Claims. (Cl. 95-89) This invention relates to photography and, more particularly, to photographic apparatus for processing photographic materials.

Generally, the present invention is concerned with apparatus comprising means for making frame-by-frame exposures of a photosensitive sheet and then processing each successive frame by superposing the exposed portion of the photosensitive sheet with a second sheet and distributing a processing liquid between the two sheets as a layer covering the exposed portion. The photosensitive sheet comprises a layer of a heavy metal photosensitive salt, such as silver halide, on a suitable support. The processing liquid initially provided as a mass extending transverse a portion of the photosensitive sheet adjacent the exposed frame is distributed between the sheets iby advancing the superposed sheets, commercing with the portion containing the mass of processing liquid between a pair of juxtaposed pressure-applying members.

In apparatus of the type with which the present invention is concerned, the pressure-applying members, at least one of which comprises a roll, engage the superposed sheets to advance the sheets in response to the rotation of the roll. Since the processing liquid should not be distributed over more than one frame, it is desirable to' separate the pressure-applying members to allow any excess processing liquid to be collected on the area of the superposed sheets intermediate successive frames and then advanced between the pressure-applying members without being further distributed between the superposed sheets.

The invention is shown incorporated in a device for making copies of original documents. Features common' to document copiers of this type include means for feeding an original document into the apparatus and superposing it with the photosensitive sheet during exposure thereof, separating the original from the photosensitive sheet, superposing the photosensitive sheet with a second sheet, introducing the processing liquid between the two sheets and advancing the superposed sheets between a pair of juxtaposed members to distribute the processing liquid between the sheets.

An object of the present invention is to provide, in a device of the type described for distributing a processing liquid on a photographic sheet, novel means for separating the juxtaposed pressure-applying members and advancing the sheet between the separated members.

Another object is to provide apparatus of the type described in which the means for advancing the superposed sheets between the separated members utilizes the same advancement means used to advance the sheets when the members are in juxtaposition.

Still another object is to provide novel means for separating the juxtaposed pressure-applying members to terminate distribution of the processing liquid after varying lengths of the superposed sheets have been covered with the processing liquid.

Further objects include providing novel means for preventing any excess processing fluid from escaping at the lateral edges of the superposed sheets during the period in which the pressure-applying members are spaced apart.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the apparatus possessing the construction, combination of elements and arrangement of parts which are exemplified in the fol- Patented August 16, 1966 lowing detailed disclosure, and the scope of the application of which will be exemplified in the claim.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in conjunction with the accompanying drawings wherein:

FIGURE 1 is a perspective view of document-copying apparatus embodying one form of the present invention;

FIG. 2 is a perspective view of components of the apparatus of FIGURE 1 shown with the housing of the apparatus open in an inoperative position;

FIG. 3 is a sectional view of the apparatus of FIG- URE 1, the section being taken substantially midway between the sides of the housing;

FIG. 4 is a fragmentary view, partially in section, of a fluid container used for introducing processing fluid into the apparatus;

FIGS. 5 and 6 are perspective fragmentary views, partially in section, of apparatus comprising the present invention.

Reference is now made to FIGS. 1 through 3 wherein is illustrated one form of photographic document-copying apparatus embodying the invention. Housing 10, mounting and enclosing the operative components, comprises an upper housing section 12 pivotally secured to a lower housing section 14 by a hinge 16, said hinge being located at one end, called the rear end, of the apparatus. The two sections are pivotable between the closed or operative position shown in FIGS. 1 and 3, and the open or inoperative position shown in FIG. 2 in which the housing sections are separated to permit loading the photographic sheet material into the apparatus.

Upper housing section 12 comprises an upper wall 18 in which are located an inlet passage 20 and an exit passage 22 through which the original document to be copied can be introduced into and fed from the apparatus. Inlet passage 20 is defined by convergent walls which may be designated forward wall 24, rear wall 26 and side walls 28. Exit passage 22 is similarly defined by forward wall 30, rear wall 32 and side walls 34. An opening 36, located adjacent a storage area in which a number of the containers are held prior to use, is also located in upper wall 18. The cover '46 of opening 36 is pivotably connected to upper wall 18 by hinges 48. Housing section 12 also comprises side walls 50 and 52, designated left and right side walls respectively, a forward wall 54 and a rear wall 56 to which the upper portion of hinge 16 is connected. A tapered opening 58 is located in left side Wall 50. Lower housing section 14 comprises a forward wall 60, portions of which serve to define withdrawal opening 62, bottom wall 64, left and right side walls 66 and 68, and rear wall 70 to which the lower portion of hinge 16 is connected.

The operative components of the document-copying apparatus are mounted on support members or chassis carried within housing 10 on the upper and lower housing sections. These support members include a lower chassis 72 comprising a base plate 74, which rests on bottom wall 64 of housing section 14, and side plates 76 extending upwardly from the base plate. The upper chassis comprises support members 78 extending downwarde ly from upper wall 18 of housing section 12, and securely mounted to'upper wall 18.

Lower chassis 72 includes means for mounting the photosensitive and image-receiving sheet used in the apparatus. The photosensitive sheet 80, preferably in the form of an elongated strip, is supplied on a conventional spool 82, said spool being mounted at its ends for rotation between side plates 76 near the rear end of housing 10. The image-receiving sheet 84, also in the form of an elongated strip, is contained on a similar spool 86,

mounted for rotation between side plates 76 near the forward end of the apparatus.

The apparatus includes means for exposing a photosensitive sheet comprising two sources of illumination and means for conducting the-photosensitive sheet and original document in superposition past the illumination sources. Each source comprises a light-transmitting cylindrical bar 88 enclosed in an opaque cylindrical tube 90 which is provided with an axial slot 92 equal in length to the width of the photosensitive sheet for transmitting the actinic light emitted from bar 88 to the photosensitive sheet. The light source for each \bar comprises l3. small incandescent lamp mounted within the end section of tube 90 adjacent to the end of bar 88 within the tube. One illumination source is mounted on upper support members 78 in upper housing section 12; the other on lower chassis 72 in lower housing section 14. As the superposed photosensitive sheet and original document are guided between the two sources, the photosensitive sheet may, by utilizing one source or the other, be subjected to either a direct exposure wherein the photosensitive sheet is exposed to light transmitted through to it through the original document, or to a reflex exposure wherein the actinic light is transmitted through the photosensitive sheet to the surface of the original document and is then partially reflected back to the photosensitive sheet to form a developable image therein.

The means for guiding the photosensitive sheet and original document between the two illumination sources include a transparent cylindrical tube 94 surrounding the upper illuminating source and mounted for rotation on upper support members 78. An elongated guide rod 96 is mounted between side plates 76 with its axis parallel with the axis of tube 94 and its periphery spaced slightly at a distance from the periphery of tube 94. A guide roll 98 engaging tube 94 along its periphery is mounted for rotation between side plates 76 with its axis parallel to tube 94.

Photosensitive sheet 80 is conducted from spool 82, between guide rod 96 and tube 94, around a portion of the cylindrical surface of tube 94 and between the tube and'guide roll 98. The axial slots 92 in tubes 90 are positioned so that the actinic light transmitted from either of bars 88 will expose the portion of the photosensitive sheet 80 that is supported by cylindrical tube 94 between guide rod 96 and guide roll 98.

.During exposure of photosensitive sheet 80, an original document, designated 100 in FIG. 3, is superposed with the photosensitive sheet between the latter and tube 94. The original document is introduced into the apparatus through inlet passage 20 and guided and fed between guide rod 96 and tube 94 into superposition with photosensitive sheet 80.

The means for guiding the original document and for sealing the inlet passage against light comprise a pair of rolls, inlet roll 102 and central roll 104, mounted for rotation in juxtaposition between upper support members 78. Rolls 102 and 104 engage the original document along a line lying in a plane substantially tangent to the surface of tube 94 at a line closely adjacent rod 96 and, in conjunction with light-sealing element 106 which extends downwardly from rear wall 26 to a point closely adjacent rod 96, and light-sealing element 108 which extends downwardly from central roll 104 to a point closely adjacent tube 94, advance and guide the original document between rod 96 and tube 94 into superposition with the photosensitive sheet.

The apparatus includes means for separating original document 100 from the photosensitive sheet following exposure-of the latter and for guiding the original out of the apparatus, comprising outlet feed roll 110 mounted for rotation between upper support members 78 and juxtaposed with central roll 104. Outlet roll 110 is so :positioned that it and central roll 104 engage original document 100 along a line lying in a plane substantially tangent to both tube 94 and guide roll 98. As the original document is advanced between tube 94 and guide roll 98, its leading edge tends to move in a plane tangent to tube 94 and roll 98 and into the bite of outlet feed roll 104 and central roll 11%. A pair of light-sealing elements 112 and 114, which extend downwardly from rolls 104 and 110, respectively, to positions adjacent tube 94 and roll 98 assist in separating the original document from the photosensitive sheet and guiding the original into the bite of the outlet roll. Elements 106, 108, 112 and 114 also function to prevent light from entering the apparatus through the inlet and exit passages and fogging or overexposing the photosensitive sheet.

After the original document has been separated from the exposed sheet and guided out of the apparatus, the exposed photosensitive sheet is processed in conjunction with a second or image-receiving sheet 84 to form a copy of the original document on the second sheet. The means for processing the two sheets include a pair of pressureapplying rolls 116 and 118. Roll 116 is'mounted be-' tween side plates 76 of lower chassis 72 and is driven in a counterclockwise direction (as seen in FIG. 3) by an electric motor (not shown) mounted within lower housing section 14. Roll 118 is mounted for rotation between a pair of movable members 120 whichare mounted on side plates 76 so as to provide for limited movement of roll 118 relative to roll 116. A spring mechanism 122 is provided for biasing roll 118 toward upper roll 116.

The exposed portion of photosensitive sheet is guided from between roll 98 and tube 94 into the bite of pressure-applying rolls 116 and 118, and image-receiving sheet 84 is conducted from spool 86 between spool 86 and guide rod 124 mounted between side plates 76 with its axis parallel to spool 86, around roll 116 and then between rolls 116 and 118 into superposition with the photosensitive sheet. Since spools 82 and 86 are both mounted on lower chassis 72, the photosensitive and image-receiving sheets may be threaded in superposition between rolls 116 and 118 while housing sections 12 and 14 are separated in the inoperative position.

The processing liquid is supplied in an elongated tubular container very much like a conventional drinking straw. This container, designated 126 in FIG. 4, includes a cavity of substantially uniform cross-section, approximately equal in length to the width of the exposed photosensitive sheet and filled with the processing liquid. Both ends of the container are sealed with one end, designated 128, adapted to become unsealed to form a discharge mouth through which the processing liquid may be discharged in response to a hydraulic pressure generated within the enclosed liquid. In the disclosed apparatus, the container is positioned transverse the portion of the image-receiving sheet lying between guide roll 124 and pressure-applying roll 116 with end 128 located adjacent the margin of the image-receiving sheet most distant from opening 58. The portion of the container adjacent the lateral edge of the image-receiving sheet nearest opening 58 is then compressed and the container withdrawn from the apparatus. This withdrawal creates a hydraulic pressure in the enclosed liquid and causes end 128 of the container most distant from opening 58 to become unsealed and the processing liquid to be ejected therefrom in the form of a uniformly distributed elongated mass extending across the width of the image-receiving sheet.

The portion of the image-receiving sheet carrying the liquid mass is then superposed with the portion of the photosensitive sheet located adjacent the leading edge of the exposed area, and the superposed sheets are then advanced between the pressure-applying rolls by the rotation cent the pressure-applying rolls on the side thereof nearest withdrawal opening 62 for severing the exposed and processed portion of the superposed sheets from the remaining sheet material as the superposed sheets pass between the knife and anvil. A pair of withdrawal rolls 130 are mounted in juxtaposition for rotation on lower chassis 72 within housing and adjacent withdrawal opening 62 to engage the processed sheets and advance them out of the housing. After the superposed sheets pass out of the housing, they may be separated and the photosensitive sheet discarded. The image-receiving sheet comprises a copy of the original document.

As previously noted, the processing liquid is dispensed from the container and deposited on the image-receiving sheet as a mass extending transversely across the portion of sheet 84 lying between guide rod 124 and pressureapplying roll 116. As the pressure-applying rolls advance the sheets in superposition, the mass of processing liquid is distributed between the superposed sheets as a layer extending transversely the width of the exposed area of the photosensitive sheet. After the entire exposed area has been covered with a layer of processing liquid, a portion of the mass may still remain to the left (viewing FIG. 3) of the pressure-applying rolls. To prevent the excess fluid from being further distributed, it is desirable to collect it between a portion of the superposed sheets by momentarily separating the pressure-applying rolls and advancing the portion of the sheets containing the excess liquid between the rolls and out of the apparatus.

In most apparatus for treating a photosensitive sheet by advancing it between a pair of juxtaposed pressure-applying members, the members are separated for collecting the excess liquid by either forcing the support on which one of the members is mounted away from the other member by means comprising the apparatus, or by wedge-like elements provided on one of the superposed sheets. The latter method, in which the elements must be mounted on the sheet during the manufacture of the sheet, is most suitable in a device in which the areas to be treated are of predetermined, uniform lengths. When the exposed areas may vary in length, however, the elements must be mounted to provide for the greatest possible length, and a considerable amount of sheet material is wasted when a shorter area is exposed. While the former method may be adapted to process varying lengths of sheet material, it presents problems in a device in which the sheet material is advanced by the pressure-applying members. When the members are separated, this frictional engagement between the members and the sheet material is lost and another means must be provided to advance the portion of the sheets containing the excess liquid between the separated members.

The present invention comprises novel means for separating the pressure-applying members after varying lengths of the superposed sheets have been processed and utilizing the same advancement means used to advance the sheets when the members are in juxtaposition to advance the sheets between the separated members. As illustrated in FIGS. 5 and 6, the invention comprises a pair of L- .shaped spacing elements 216, mounted coaxially with pressure-applying roll 116 at the opposite ends thereof for rotation relative to roll 116. The leg 218 of elements 216 which overlies the cylindrical surface of roll 116 comprises a substantially rectangular section of a cylindrical shell having an inner radius approximately equal to the radius of the pressure-applying roll. The edges of leg 218 parallel to the axis of roll 116 may be tapered to facilitate the passage of the leg between the pressure-applying rolls. The circumferential width of leg 218 is slightly greater than the length of the portion of the superposed sheets required to contain the excess fluid. The other leg of elements 216 comprises a ring 222, surrounding the shaft 224 on which roll 116 is mounted. This ring is urged against a collar 226, mounted on shaft 224-on the side of ring 222 nearest the side walls of housing 10, by a spring 228 located between ring 222 and the adjacent end of the pressure-applying roll. The frictional contact between collar 226 and ring 222 causes the spacing elements to tend to rotate in the same direction and at the same speed as pressure-applying roll 116 from the position shown in FIGS, 5 and 6, in which the elements are spaced from the area of juxtaposition of rolls 116 and 118, to a position intermediate the rolls, at the opposite ends thereof, in which the pressure-applying rolls are spaced apart from one another and the superposed sheets are juxtaposed between elements 216 and roll 118.

When spacing elements 216 are located between the pressure-applying rolls, roll 118 is forced downward'and away from roll 116 to provide a space between the rolls equal to the combined thickness of leg 218 and the superposed sheets. Elements 216 are further advanced between the separated rolls by the continued rotation of roll 116 to advance the portion of the superposed sheetscontaining the excess processing fluid between the rolls. It should be noted that a number of equivalent means, such 'as'slip clutches, may be provided to advance the spacing elements in response to the rotation of one of the pressureapplying rolls.

It is apparent that the pressure-applying rolls must not be separated until the entire exposed area of the photosensitive. sheet has been covered with a layer of processing fluid, and that the rolls should be separated very shortly after the exposed area has been covered if the amount of sheet material required to produce each copy is to be kept to a minimum. The illustrated apparatus includes means for insuring that spacing elements 216 rotate between and separate the pressure-applying rolls immediately after the exposed area has been covered regardless of the length of the particular exposed area.

As shown in FIGS. 5 and 6, a control rod 238 is mounted on lower chassis 72 parallel to the pressure-applying rolls for limited movement in an axial direction. When rod 238 is in the positionillustrated in FIGS, towards which it is biased, a pair of restraining fingers 230 mounted on the rod engage a pair of pins 232 extending radially outward from rings 222 on each of spacing elements 216 and prevent the spacing elements from rotating in response to the rotation of roll 116 to advance the superposed sheets.

As previously mentioned, the invention is shown incorporated in a semi-automatic, electrically-operated document copying device. As the original document is ad vanced out of the apparatus through exit passage 22, after being exposed in superposition with the photosensitive sheet, the trailing edge of the document releases a microswitch 214- mounted on light sealing'element 114 (see FIG. 2) and momentarily activatesa solenoid 234 shown in FIG. 5. Solenoid 234 acts through a pivotable member 236 to move the spacer control rod in an axial direction, thereby releasing pins 232and allowing the spacing elements 216 to rotate in the direction of sheet movement in response to the rotation of roll 116. Legs 218 of each spacing element are frictionally engaged between the image-receiving sheet 84 and pressure-applying roll 116 to help insure that both spacing elements rotate at the same speed. Switch 214 is timed to release pins 232 so that the leading edge of each spacing element will be introduced between the pressure-applying rolls immediately after the trailing edge of the exposed portion of the photosensitive sheet has been covered with a layer of processing liquid. It should be evident that both the size of the exposed are-a and the length of the superposed sheets that is covered with processing fluid before the rolls are separated are entirely dependent on the length of the particular document being copied.

When spacing elements 216 are located between the pressure-applying rolls the later-a1 edges of the portion of the superposed sheets containing the excess processing liquid are engaged between legs 218 of elements 216 and roll 118. The frictional engagement between collars 226 and rings 222 of spacing elements 216, and between legs 218 and the peripheral surface of roll 116, insures that the spacing elements, in conjunction with roll 118, advance the portion of the superposed sheets between the separated rolls in response to the continued rotation of roll 116.

Spring mechanism 122 forces rolls 116 and 118 back into juxtaposition as soon the trailing edge of legs 218 of the spacing elements has passed between the pressureapplying rolls. Elements 216 continue to rotate in response to the rotation of roll 116 until they are in the position shown in FIG. where restraining fingers 230 engage pins 232 to prevent any further rotation. The portion of the superposed sheets containing the excess processing liquid is now'located to the right (viewing FIG. 3) of the pressure-applying rolls.

In addition to frictionally engaging and advancing the superposed sheets, juxtaposed spacing elements 216 and roll 118 also prevent any of the excess processing liquid from escaping at lateral edges of the superposed sheets as the portion of the sheets containing the excess liquid is advanced between the separated pressure-applying rolls.

While the present invention has been described with reference to an electrically operated document copying device, it should be evident that it could be incorporated in any apparatus in which a processing liquid is distributed by a pair of juxtaposed members which also function to advance the sheets.

Since certain changes may be made in the above apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In photographic apparatus including a pair of juxtaposed pressure-applying members between which a photosensitive sheet is advanced to distribute a processing liquid against said sheet, said members being movable toward and away from one another, and means for rotating at least one of said members in engagement with said sheet for advancing said sheet between said members, the combination therewith of means for simultaneously separating said member to terminate distribution of said liquid and engaging a lateral marginal portion of said sheet between said members to advance said sheet relative to and between said members during the separation thereof.

2. In photographic apparatus including a pair of juxtaposed pressure-applying members between which a photosensitive sheet is advanced to distribute a processing liquid against said sheet, said members being movable toward and away from one another, and means for rotating at least one of said members in engagement with vance said sheet between said members during separation thereof, the last-named means comprising an element mounted adjacent said members for movement from a first position spaced from the area of juxtaposition of said members to a second position intermediate said members between said one member and said marginal portion of said sheet, and drive means in engagement with said element for advancing said element from said first position to said second position in the direction of movement of said sheet between said members.

3. The apparatus of claim 2 in which said drive means engage said element in said second position for advancing said element in engagement with said sheet in response to the rotation of said one member to advance said sheet between said members during the separation thereof.

4. The apparatus of claim 3 in which said drive means engage said element for advancing said element from said second position to said first position in the direction of movement of said sheet between said members in response to the rotation of said one member.

5. The photographic apparatus of claim 2 in which said drive means include a slip clutch engaged with said means for rotating said one member.

6. The photographic apparatus of claim 5 including control means for engaging said element to prevent the movement thereof from said first position during distribution of said liquid against said sheet, said control means being movable from engagement with said element to permit the movement thereof to said second position to terminate distribtuion of said liquid.

7. The photographic apparatus of claim 2 in which said one member is a roll and said element is mounted for rotation coaxially with said roll.

8. The photographic apparatus of claim 7 in which said element includes a first section extending radially on which said element is mounted for rotation and a second section extending axially of said roll and disposed closely adjacent the peripheral surface of said roll to engaging said sheet. 7

9. The photographic apparatus of claim 8 in which said element is frictionaly coupled with said roll and means are provided for engaging said element to prevent rotation thereof into said second position during rotation of said roll and distribution of said liquid.

10. In photographic apparatus including a pair of juxtaposed pressure-applying members, at least one of which comprises a roll, between which a photosensitive sheet is advanced to distribute a processing liquid against said sheet, said members being movable toward and away from one another, and means for rotating said roll in engagement with said sheet for advancing said sheet between said members, the combination therewith of means for separating said members to terminate distributionof said liquid and for engaging said sheet to advance said sheet between said members during the separation thereof, the last-mentioned means comprising a pair of elements mounted adjacent the opposite ends of said'members for movement from first positions spaced from the area of juxtaposition of said members to second positions intermediate said members between one of said members and lateral marginal portions of said sheet; and drive means in engagement with said roll and each of said elements for advancing said elements in the direction of movement of said sheet from said first positions to said second positions.

11. The photographic apparatus of claim It) in which said photosensitive sheet is processed by superposing it with a second sheet and advancing said sheets in superpoition between said members to distribute said processing liquid between said sheets and in which said elements compressively engage said lateral marginal portions of said sheets adjacent said opposite ends of said members during the period of separation of said members to prevent said processing liquid from flowing between the lateral edges of said sheets of said marginal portions.

12. The photographic apparatus of claim 10 in which said drive means engage said elements in said second positions for advancing said elements in engagement with said sheet in response to the rotation of said roll to advance said sheet between said members during the separation thereof.

13. The photographic apparatus of claim 12 in which 14. The photographic apparatus of claim 10 in which said drive means include slip clutches engaged with said means for rotating said roll.

15. The photographic apparatus of claim 14 including control means for engaging said elements to prevent the movement thereof from said first positions during the distribution of said liquid against said sheet, said control means being movable from engagement with said elements to permit the movement thereof to said second positions to terminate distribution of said liquid.

16. The photographic apparatus of claim 10 in which said elements are mounted for rotation coaxially with said roll at opposite ends thereof and in which each of said elements includes a first section extending radially on which said element is mounted for rotation and a second section extending axially of said roll and disposed closely adjacent the peripheral surface of said roll for engaging said sheet.

17. The photographic apparatus of claim 16 in which each of said elements are frictionally coupled with said roll and including means for engaging said elements to prevent rotation thereof into said second positions during distribution of said liquid.

18. The photographic apparatus of claim 16 in which said photosensitive sheet is processed -by superposing it with -a second sheet and advancing said sheets in superposition between said members to distribute said processing liquid between said sheets and in which said second sections of said elements compressively engage at least a portion of the lateral edges of said sheets between said second sections and one of said members during the period of separation of said members to pnevent said processing fluid from flowing between said lateral edges.

References Cited by the Examiner UNITED STATES PATENTS 7/1961 Eloranta 9589 XR 6/1964 Mason et al 9589 

1. IN PHOTOGRAPHIC APPARATUS INCLUDING A PAIR OF JUXTAPOSED PRESSURE-APPLYING MEMBERS BETWEEN WHICH A PHOTOSENSITIVE SHEET IS ADVANCED TO DISTRIBUTE A PROCESSING LIQUID AGAINST SAID SHEET, SAID MEMBERS BEING MOVABLE TOWARD AND AWAY FROM ONE ANOTHER, AND MEANS FOR ROTATING AT LEAST ONE OF SAID MEMBERS IN ENGAGEMENT WITH SAID SHEET FOR ADVANCING SAID SHEET BETWEEN SAID MEMBERS, THE COMBINATION THEREWITH OF MEANS FOR SIMULTANEOUSLY SEPARATING SAID MEMBER TO TERMINATE DISTRIBUTION OF SAID LIQUID AND ENGAGING A LATERAL MARGINAL PORTION OF SAID SHEET BETWEEN SAID MEMBERS TO ADVANCE SAID SHEET RELATIVE TO AND BETWEEN SAID MEMBERS DURING THE SEPARATION THEREOF. 